Cooling mechanism for grlnding-m i lls



(No Mddel.) 2 Sheets-Sheet 1.

' J. FITZGERALD.

COOLING MECHANISM FOR GRINDING MILLS.

No. 255,964. Fly Patented A pr. 4,1882.

N PETERS. Pholo-Lilhugnpber. Walhillgion. B. C.

2 Sheets-Sheet 2.

(No Model.)

J. FITZGERALD.

COOLING MECHANISM FOR GRINDING MILLS.

( I Patented Apr. 4,1882.

u. PETERS. Phaln-Lilhognphun Washington. 0 c.

UNITED STATES PATENT OFFICE.

JOHN FITZGERALD, OF BROOKLYN, NEW YORK.

COOLING MECHANISM FOR GRINDING-MILLS.

SPECIFICATION forming part of Letters Patent No. 255,964, dated'April 4,1882,

Application filed December 4, 1880.

To all whom it may concern:

Be it known that I, JOHN FITZGERALD, of the city of Brooklyn, county ofKings, and State of New York, am the inventor -of certainImprovementsinOoolingMechanismforGrinding-Mills, of which the followingis a full, clear, and exact description, reference being bad to theaccompanying drawings, forming part of the same.

My invention relates to grinding-mills; and it consists in thecombination of parts and devices hereinafter particularly described, andconstructed and arranged as set forth, whereby the cooling of the upperand lower grinding-stones is accomplished, and whereby either air orwater may be employed at pleasure as thecooling medium, and the changemay be made from one to the other, if desired, without rearrangement oralteration of the parts, all as more at length recited in the claims.

Figure 1 is a side elevation of a grindingmill embodying my invention.Fig. 2 is a plan of the same. Fig. 3 is a plan in detail of a circularwater-escape trough, which constitutes one part of myinvention, andwhich is hereinafter fully described. Fig. 4 is a vertical centralsectional view of the mill. Fig. 5 is an interior plan of the casing ofthe upper or stationary grinding-stone, the stone being removed todisclose fully the arrangement of the cooling-chambers and theirsupplyand exhaust pipes. Fig. 6 is a similar view of the casing of thelower ormoving grinding-stone, said stone being removed.

The object of my present invention is twofold: first, the accomplishmentof the cooling of both the upper or stationary grinding-stone and thelower or moving grinding-stone; and, second, such an arrangement andconstruction of the devices employed to accomplish the cooling of thestones that said devices are adapted for the use of either air or wateras the'cooling medium, and that a change maybe made from one to theother without alteration or rearrangement of said devices, and alsowhereby the centrifugal force generated in the lower or revolvinggrinding-stone is utilized to facilitatethe circulation of the coolingmedium over and around the stone, and more particularly when water isemployed, said cooling medium being admitted to the cooling-chambers atthe center of the stone and discharged at the periphery.

A is the upper or stationary grinding-stone, and B the lower or movinggrinding-stone.

A is the casing which contains the coolingchambers of the upper stone,A, and in which the same is supported and centered, which ispreferablyaccomplishedbymeansofset-screws, as shown. y

B is the casing which contains the coolingchambers of the lower stone,B, and in which the same is seated and centered, preferably by means ofsimilar set-screws, as shown.

C is the spindle upon which thelower stone, B, is hang, and by means ofwhich it is revolved.

D is the frame which supports the various parts.

E is the hopper into which the material to be ground is placed, and fromwhich it is fed through the adjustable gate 0 to the stones A B, thesaid hopper being supported by lugs e, bolted to the top of the frame,as shown, and the material passing to and between the stones through theopening 0 in the upper grinder, A, and its casing A. A conical plate ordisk, F, is secured upon the center of the lower or moving stone, B, andis held in place by bolts passing into the casing B of the said lowerstone, and the inclined outer face of this plate serves to guide thematerial to be ground between the stones. The interior of this plate isprefer-ab] y chambered, as at f, and this chamber communicates with thechamber 1) at the center of the casing B of the lower stone, whichchamber is about the hub of said casing and stone, as shown in Fig. 4.

To accomplish the cooling of the upper or stationary stone, A, I employthe following devices: Water or air is admitted under pressure throughthe main supplypipe 0, and passes from thence through the branch pipes cc, which may be more or less in number, as will be hereinafter apparent,to the cooling chambers about the upper stone. These chambers areconstituted as follows: The casing A of the stone A is of somewhatgreater diameter than the stone itself, so that a space or chamber, a,exists between the outer edge of the stone and the outer circumferentialwall or flange of the casing. Upon the interior face or roof of thecasing is cast, fixed, or otherwise formed a circular projection, a,which is so placed that when the stoneis seated in the casing theprojection will fit upon the upper facing or back of the stone at ornear to the outer edge thereof, as seen in Fig. 4, whereby a chamberupon the back of the stone and a separate and distinct one on thecircumference are constituted.

The chamber a about the circumference of the stone is then divided intosubchnmbers by means ofthe radial partitions a and these subdivisionsmay be more or less in number; but I find that for all practicalpurposes a subdivision into two distinct subchambers by means ofdiametrically-opposite radial partitions, as shown in Fig. 5, ispreferable. Into each of these circumferential chambers,and preferablymidway between the ends thereof, opens one of the supply-pipes c 0,through which the cooling medium is admitted, and as many supply-pipesas there are subdivisions should be provided. The chamber constitutedupon the back of the stone, as hercinbefore described, is then dividedinto subchambers by means of the radial part itionsa a extentlingfromthe interior circumferential wall of the casing to the circularprojection or partition 0/, and by means of the partitions a, which arecarried inward to the interior circumferential wall, as shown in Fig. 5.These subdivisions may be more or less in number; but I find itpreferable to arrange them as shown in Fig. 5, to constitute foursubchambers, a a a a", and to have them in pairs in their positionsrelative to the subdivision of the circumferential chamber. At the endsof each subdivision of the chamber a which are most remote from thesupply-pipes c c are cut or formed gates or openings c in the projectingpartition to, a separate one opening into each of the subdivisions 40 aand a7 a constituting the pair adjacent to each subdivision of a.

D is the discharge or escape pipe leading from the cooling-chambers ofthe upper stone, A. This pipe is convenientlyprovided with branches atd, leading preferably to each pair of adjacent subdivisions a a and c"a, as shown, the partitions a a, which separate said pairs, being inthis arrangement preferably cut away, as shown, so that communication ishad to a single one of the branch pipes of D from both of thesubdivisions constituting the pair, as shown. I prefer that there shouldbe within each of the subdivisions a a- (0 a irregularly-placedprojections or lugs a, which are cast or otherwise formed or fixed uponthe interior face of the casing and extend to the upper face of thestone A, and which serve to break up and thoroughly distribute the coo1-ing medium over the face of the stone.

It is evident that the cooling medium, whether air or water, enteringthrough c 0, will pass through each of the subdivisions of the chamheror around the circumference of the stone to the gates at each of theopposite ends thereof, and through these gates into each of the pairs ofchambers 60 a and co a over the upper face of the stone, and thence outthrough d d to the discharge-pipe D, and that this circulation beingmaintained, the effectual cooling of the upper stone will beaccomplished. It is also evident. that the stone A being stationary, andconsequently the circulation of the cooling medium being caused by thepressure or headway thercof, with no centrifugal force to impede orovercome it, the circulation of the cooling medium may be the reverse ofthat specitied without materially changing the principle of my describedinvention.

To effect the cooling of the lower or moving stone, B, I employthefollowing devices: The main supply-pipe 0 leads to a stuffing-box, 6in the roof of the hopper, and from this box, and having play therein topermit the wear of the stones to be taken up, the pipe 0 leads downthrough the hopper, a stuffing-box, a, being arranged in the opening inthe floor thereof, through which the said pipe passes to and through thecrown of the plate F, with the chambered interior f of which itcommunicates. By this means the cooling medium, be it air or water, isadmitted under pressure to the cooling-chambers of the lower stone, B.These chambers are constituted as follows: About the hub of the casingwhich holds the stone is formed the chamber 1), as shown plainly in Fig.6. Upon the interior face of the easing B is cast or otherwise formed orfixed the circular projection I), which is so placed that when the stoneis seated in the casing the projection b will fit upon the back of thestone at or near the outer edge thereof, thus forming a chamber or spacebetween the back of the stone and the interior face of the casing, andthe diameter of the casing being somewhat greater than the diameter ofthe stone, a space or chamber is constituted between the edge of thestone and the outer circumferential wall of the casing, as seen at W.

The space or chamber formed on the face of the stone by the projectionb, I divide into chambers b b b b b b by means of the radial partitionsb I) b b I), and these chambers or divisions may be more or less innumber; but I find it preferable that they should be as shown andspecified for the most effectual operation of my invention. Thecircumferential space 0 I also then divide into chambers, and I find itpreferable so to divide this space that the chambers upon the back ofthe stone are arranged in pairs in their relation to the subdivisions ofthe circumferential chamber b and this I accomplish by extending eachalternate one of'the before-named radial partitions out to a junctionwith the face of the circumferential wall of the casing, as shownplainly in Fig. 6.

If desired, the chamber 1)? may be divided into chambers equal in numberto the subdi- IIO visions ofthe chamber on the back ofthe stone. Intoeach one of the chambers on the face of the stone constituting a pairare gates 11 opening from the central hubchamber, b, and at a point ineach of said chambers most remote from said gate b in the partition I)is a gate, I1 opening into the circumferential chamber, the gates of twoadjacent chambers preferably opening into the same subdivision of saidchamber b At the point in each subdivision of said circumferentialchamber most remote from the gates b and leading into into it from thechambers 12 b, &c., are discharge-openings b" in the plate or wall ofthe casing, and said discharge-openings are preferably provided withdownwardly-extended short pipes or nozzles I), as shown in Fig. 4, whichrange in their revolution with the stone B over a circular trough, G,which is supported on a cross-piece of the main frame. From this troughan overflow-pipe, g, extends to the main discharge-pipe I), Fig. 4.

I find it preferable to arrange the irregularly-placed projections I) inthe chambers on the face of the stone, to serve the same purpose as thatnamed for the projection a.

It is evidentthat the cooling medium,whether air or water, admittedunder pressureto the chamber b, will pass through the gates D into eachchamber of the several pairs, be they more or less in number, on theback of the stone, and, circulating through these chambers over the backof the stone, will pass thence from each pair through gates b to one ofthe subdivisions of the circumferential chamber, and thus aroundthecircumference ofthe stone, and from thence will escape through theopenings I)", and that when water is the cooling medium it will becaught in the trough G and carried from thence to the main dischargep pIn cooling devices which admit the cooling medium at the periphery ofthe stone and discharge it at the center, or which return it to thecenter for discharge, the centrifugal force generated by the revolutionof the stone has to be overcome by pressure or headway given to thecooling medium; but it is evident thatby means of my described devicesand their construction and arrangement upon said stone, the coolingmedium being admitted to the chambers at the center of the stone andwholly discharged at the periphery thereof, I am enabled to utilize thesaid centrifugal force in assisting the rapid and complete circulationof the cooling medium over the face of and around the circumference ofthe stone, and to facilitate its discharge, which takes place wholly atthe periphery of the stone.

It is also evident that either water or air may be employed as thecooling medium, or that a change may be made from one to the other atpleasure without altering, rearranging, or disturbing my describeddevices.

The circumferential chambers on each of the stones A and B areclosed inby means of rings H H, respectively, which are fitted upon the peripheryof the stones and secured to the outer walls or flanges of the casings,as seen in Fig. 4. 7

Upon the pipe 0 within the hopper E may be secured the stirrer and mixer6 which will thus revolve with the pipe 0 within the hopper and assistin feeding the material to be ground to the stones.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. In a grinding-mill, the combination, with the upper or stationarygrinding-stone, A, of the casing A and ring H, said casing being ofgreater diameter than the stone, and having the circular projection aupon its inner face, as described, thus constituting a circumferentialchamber, a, about the periphery and a chamber upon the back of thestone, said circumferential chamber being divided by radial partitionsinto chambers more or less in number, each subdivision being providedwith an inlet-pipe about midway between the ends thereof, and with agate at each end thereof opening into one of each of the chambers intowhich the aforesaid. chamber 011 the back of the stone is divided bymeans of radial partitions, as shown, and which subdivisions are of sucha number and arrangement relatively to the subdivisions of thecircumferential chamber as to be in pairs, as specified, each pair beingprovided with a common outlet-pipe, all as described, and for thepurpose set forth.

2. In a grinding-mill, the combination,with the lower or moving stone,B, of thecasing B and ring H, said casing being of greater diameter thanthe stone, and having the circular projection 1) upon its inner face, asdescribed, thus constituting a circumferential chamber, b about theperiphery of the stone and a chamber upon the back of the stone, saidchamber on the back of the stone being divided by radial partitions intochambers more or less in number, each subdivision having an inlet-gate,b, leading into itfrom a chamber, b, about the hub or center of thestone, and a gate, b leading from it at a point in its opposite wallmost remote from said inlet-gate into a subdivision of the aforesaidcircumferential'chamber on the periphery of the stone, which subdivisionis provided with adischargeopening, I), ata point in the wall thereofmost remote from the gate b as described, and for the purpose specified.

3. In a grinding-mill, the combination,with the lower or moving stone,B, of the casing B and ring H, said casing being of greater diameterthan the stone, and having the circular projection 11 upon its innerface, as described, thus constituting a circumferential chamber, 11about the periphery ofthe stone and a chamber upon the back of thestone, said chamber on the back of the stone being divided by ra= dialpartitions into chambers more or less in number, each subdivision havingan inletgate, 2), leading into it'from a chamber, 11,

about the hill) or center of the stone, and a I), together with thetrough G, as described, gate, b leading from it at a point in its opandfor the purpose specified. [O posite well most remote from saidinlet-gate In Witness whereof I hereunto set my hand into a subdivisionof the aforesaid circumferthis 2d day of December,- A. D. 1880.

5 ential chamber on the periphery of the stone, JOHN FITZGERALD.

which subdivision is provided with a dis- In presence ofcharge-opening,b", and pipe I) at a point HENRY EIOHLING,

in the wall thereof most remote from the gate A. G. N. VERMILYE.

